<!doctype html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script>
        window.a=44
    </script>

    <style>
        .myDiv {
            position:   absolute;
            width:      expression(window.a+ "px");
            height:     100px;
            left:       expression(4+ "px");
            top:        expression(document.body.offsetHeight - 110 + "px");
            background: red;
        }
    </style>
</head>
<body>
     <div class="myDiv">

         aaa
     </div>
</body>
</html>